test_fstring test using script

Author: tom-pytel

Lib/test/test_fstring.py

@@ -12,12 +12,10 @@
 import dis
 import os
 import re
-import tokenize
 import types
 import decimal
 import unittest
 import warnings
-from io import BytesIO
 from test import support
 from test.support.os_helper import temp_cwd
 from test.support.script_helper import assert_python_failure, assert_python_ok
@@ -1862,10 +1860,11 @@ def __format__(self, format):
         self.assertEqual(rf"{UnchangedFormat():\xFF} {UnchangedFormat():\n}", '\\xFF \\n')
 
     def test_gh139516(self):
-        # gh-139516
-        # The '\n' is explicit to ensure no trailing whitespace which would invalidate the test.
-        # Must use tokenize instead of compile so that source is parsed by line which exposes the bug.
-        list(tokenize.tokenize(BytesIO('''f"{f(a=lambda: 'à'\n)}"'''.encode()).readline))
+        with temp_cwd():
+            script = 'script.py'
+            with open(script, 'wb') as f:
+                f.write('''def f(a): pass\nf"{f(a=lambda: 'à'\n)}"'''.encode())
+            assert_python_ok(script)
 
 
 if __name__ == '__main__':